roteamento local com openvpn: ping: sendmsg: operação não permitida

Question

Eu configurei uma vpn simples com o IP 10.0.0.1 usando

    openvpn --mktun --dev tun1
    ip link set tun1 up
    ip addr add 10.0.0.2/24 dev tun1

e eu executo um programa simpletun em duas máquinas que são respectivamente um servidor e cliente vpn. E eu fiz ping 10.0.0.1 no cliente vpn, ele funciona bem.

agora eu uso meu laptop como o cliente vpn e tentei

    [root@kitty temp]# ping 10.0.0.1
    PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
    ping: sendmsg: Operation not permitted
    ^C
    --- 10.0.0.1 ping statistics ---
    1 packets transmitted, 0 received, 100% packet loss, time 0ms

    [root@kitty temp]# ping 10.0.0.2
    PING 10.0.0.2 (10.0.0.2) 56(84) bytes of data.
    ping: sendmsg: Operation not permitted
    ^C
    --- 10.0.0.2 ping statistics ---
    1 packets transmitted, 0 received, 100% packet loss, time 0ms

mas receba o erro ping: sendmsg: Operation not permitted

informações relacionadas:

    [root@kitty temp]# ip ro
    default via 192.168.1.1 dev wlan0  proto static
    10.0.0.0/24 dev tun1  proto kernel  scope link  src 10.0.0.2
    128.93.0.0/16 via 128.93.176.116 dev cscotun0  proto none notify

    [root@kitty temp]# route
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    default         neufbox         0.0.0.0         UG    0      0        0 wlan0
    10.0.0.0        *               255.255.255.0   U     0      0        0 tun1
    128.93.0.0      sop116r.vpn.inr 255.255.0.0     UG    0      0        0 cscotun0

    [root@kitty temp]# ip add
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
        inet6 ::1/128 scope host
           valid_lft forever preferred_lft forever
    2: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
        link/ether 00:24:d7:78:71:38 brd ff:ff:ff:ff:ff:ff
        inet 192.168.1.96/24 brd 192.168.1.255 scope global wlan0
        inet6 fe80::224:d7ff:fe78:7138/64 scope link
           valid_lft forever preferred_lft forever
    3: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
        link/ether 5c:26:0a:2b:b8:06 brd ff:ff:ff:ff:ff:ff
    21: cscotun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1406 qdisc pfifo_fast state UNKNOWN qlen 500
        link/none
        inet 128.93.176.116/25 brd 128.93.176.127 scope global cscotun0
    22: tun1: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 100
        link/none
        inet 10.0.0.2/24 scope global tun1

qual é o problema em potencial aqui? obrigado!